The present invention relates to shot such as BB-shot pellets, for wild game hunting and particularly for hunting birds on wet marshlands and for clay pigeon shooting from organized skeet ranges.
Large numbers of lead shot pellets are used worldwide when hunting wild game, particularly when hunting birds. The majority of the pellets fail to hit the target, and fall relatively undamaged to the ground or settle on the bottom of waterways and lakes. With time, more and more lead pellets accumulate on the ground and on the bottoms of lakes and rivers.
Investigations have shown that over the last decennium sea birds in particular have shown signs of lead poisoning. It has been established that the birds ingest lead pellets from the ground or from the bottom of rivers and lakes in their search for food and also for gravel to assist in digestion of the food ingested.
The lead pellets remain in the gizzard of the bird for from 7 to 15 calendar days. The gastric juices produced by birds are relatively acid and have a pH of about 1 and contains mainly hydrochloric acid, and consequently large quantities of lead are leached from the pellets. The leached lead then travels through the blood vessels to vital body organs and causes suffering and, in many cases, the death of the animal or bird concerned. According to scientific research, the ability of such creatures to reproduce is also affected by the ingestion of lead. The risk increases in areas that are densely populated by sea birds, where hunting is highly intensive.
Progressively more countries forbid the use of lead shot for hunting birds on wet marsh lands, lakes, rivers and other waterways, so as to avoid subjecting the birds to lead poisoning. The use of lead shot pellets over land is also prohibited, so as to avoid lead leaching from lead pellets in natural habitats. The use of lead shot pellets on clay pigeon skeet ranges is quantitatively much greater than the use to hunt birds on wet marshlands etc. This results in an undesirable local accumulation of lead, and the use of lead shot for clay pigeon shooting thus constitutes an environmental problem.
At present time, the alternative to lead shot is iron or steel shot. Bi-shot is available, although only in very limited quantities. Steel and iron shot, however, are encumbered with other serious drawbacks and hunters have reacted strongly against the use of such shot. Among other things, the relative density of such shot is 30% lower than the relative density of lead, and therefore requires a larger explosive charge to propel the pellets, with the accompanying risk of fracturing the barrel of the gun concerned and also of lowering the penetrating force of the pellets and therewith causing more injuries than deaths to the animals or birds struck by the pellets. The use of steel and iron pellet also results in much heavier wear on the gun barrels. Sparks generated by ricochets and subsequent danger of fire also constitute a serious risk when hunting with iron or steel pellet.
There is thus a need, at least when hunting so-called swimming birds on lakes and rivers, for shot pellets which while possessing all the positive properties of lead shot pellets will, at the same time, eliminate the negative aspects of lead pellet mentioned in the introduction, such as the lead poisoning of birds, for instance. Such lead shot pellets will also preferably have a negligible influence on skeet ranges and their surroundings.
It has earlier been proposed to coat lead shot pellets with copper or nickel, so as to enhance resistance against the leaching of lead in acid environments, and shot pellets of this nature has also been sold commercially to a limited extent. GB-A 2,111,176 proposes the use of shot pellets on which a coating of tin has been electrolytically applied. Comparison tests carried out in conjunction with the production of tin coated pellet showed that a "critical" dissolution was reached within one hour in the case of conventional uncoated lead shot pellets, whereas the tin coated shot pellets showed roughly a tenfold improvement over conventional shot pellets and roughly a five-fold improvement over nickel coated shot pellets. No tin coated shot pellets have been retailed commercially, however, probably because the improved leaching resistance of the pellets has been judged insufficient to be able to eliminate reasonably the aforesaid drawbacks and problems associated with the use of lead pellets.